1. Field of the Invention
This invention relates generally to digital video, and more particularly to a system and method for distributing and managing digital video information in a video distribution network.
2. Description of the Background Art
Conventional network digital video servers operate in a multithreaded environment to distribute digital video (and corresponding audio) information to multiple client computers. The client computers in turn offer VCR-like control of the digital video information including fast forward, rewind, pause, stop and play to a user. In some embodiments, the requesting client computer waits to receive the entire digital video work before beginning playback so that the user can enjoy seamless playback. However, to store an entire digital video work, significant local disk space and other memory resources are needed.
In other embodiments, the client computer requests appropriate portions of the digital video work and presents the portions on a display device as they are received. If the application software is properly designed and the network communications channel over which the client computer and the server are operating is predictable, then these requests may be totally transparent to the user and seamless playback is achieved. However, if the digital video data is not delivered within a rather tight time window, then the client computer stalls and playback is noticeably affected. At best, this can result in jerky playback of or noticeable pauses in the digital video work. At worst, the application software may not be designed to handle a network communication failure at all, which could result in various system failures more consequential than an annoyance in the digital video work playback.
One typical solution to this problem is to design the system for the worst-case scenario to prevent the problem from ever occurring. Accordingly, overall video server throughput is computed for a worst-case bit rate which, based on current digital video compression techniques, may be over five times the average required bit rate. The worst case scenario provides a system which inefficiently uses network bandwidth. Further, this approach does not function well in an environment, such as the internet, that does not have dedicated mechanisms for assuring available network bandwidth. The traditional methodology does not scale beyond a simple Local Area Network (LAN) environment. Therefore, a system and method are needed to distribute and manage digital video information in a video distribution network environment beyond a LAN.